Crimping apparatus



Aug. 27, 1963 E. FLOYD, JR

CRIMPING APPARATUS Original Filed April 26, 1955 FIG.

FIG. 2.

INVEN TOR. EDWl/V FZOVD, JP

ATTORA/EKS United States Patent 3,101,766 CRIMPING APPARATUS Edwin Floyd, Jr., Lower Paxton Township, Harrisburg,

Pa., assignor to AMP Incorporated, Harrisburg, Pa. Continuation of abandoned application Ser. No. 504,029,

Apr. 26, 1955. This application Feb. 23, 1962, Ser.

2 Claims. (Cl. 1531) This application constitutes a continuation of my prior application, Serial No. 504,029, filed April 26, 1955, now abandoned.

The present invention relates to crimping apparatus of a type well-suited for the crimping of connector ferrules onto cores. More particularly, the present invention relates to crimping die apparatus adapted for producing a confined crimping action and for crimping a wide range of sizes of connector ferrules and cores to form strong durable connections.

In crimping connector ferrules and conductors together to form electrical connections, it has heretofore been customary to use either of two types of dies, namely, those producing a confined crimping action and those which do not. This confined crimping action occurs when the dies surround the entire perimeter of the work material, at least during the final stages of their closure. Therefore, any work material which is squeezed out of the region between the die faces during the final stages of crimping is prevented from extruding radially outwardly and is forced to flow in an axial direction of the connection.

With an unconfined crimping action, some of the work material is extruded out from between the die faces into the parting spaces between the dies on each side of the connection, i.e., a flash portion or rib is formed along opposite sides of the connection.

One of the advantages of confined crimping is that the amount of squeezing and flowing of the work material and the way in which it occurs are precisely controlled, producing optimum conditions of mechanical strength and electrical conductivity in each connection. Moreover, the perime-ters of the (completed connections from any given dies are always identical and neat in appearance, without any sharp flash portions which may cause voltage stress concentrations.

Usually dies for producing confined crimping are more complicated, and require closely fitting lateral confining parts and sometimes even requiring a number of closely fitting, relatively slidable interleaving plates. Also, dies for confined crimping are usually more diflicult to load and unload because of the lateral confining portions which limit the accessibility of the die faces, and which occasionally may cause the work to jam and resist withdrawal.

Among the many advantages of the crimping die apparatus, described herein as embodying the present invention, are those resulting from the fact that a confined crimping action is obtained without the use of any such closely interfitting lateral confining parts. The loading and unloading of the dies is easier, their operation is less critical.

Another advantage of the described embodiments of the present invention is the accommodation of a wide range of sizes of connector ferrules and cores. One of the dies is a universal die having a nest and a pair of die face extension surfaces extending tangentially from opposite side portions of the nest and diverging at an angle in the range from about 60 to about 120. The second die includes a second nest and a pair of shoulder surfaces on opposite sides of the second nest diverging at the same angle as said extension surfaces. In the closed die position, these shoulder surfaces mate with the extension surfaces producing a confined crimping action.

3,101,766 Patented Aug. 27, 1963 By changing the second die, a greater or lesser amount of the die face extension surfaces of the first die are used, depending upon the ferrule and core size being crimped, thus readily accommodating a very wide range of sizes of ferrules and electrical conductors.

In accordance with one embodiment of the present invention, these two die nests are generally V-shaped and all of the different sizes of connections produced thereby have a pleasing rhombic outline and are geometrically substantially identical in appearance regardless of their srze.

In accordance with another embodiment of the present invention, one of the die nests is generally V-shaped and the others are three-sided, and all of the diiferent sizes of connections produced thereby are pentagonal in outline and geometrically substantially identical throughout the full range of crimp sizes.

The present invention provides the advantageous operating characteristics of confined crimping-type dies, While at the same time avoiding many of the critical requirements of such dies and their closely interfitting lateral confining parts. The present invention also provides the easier loading and unloading characteristics of unconfined crimping dies.

In this specification and in the accompanying drawings are described andshown embodiments of my invention and various modifications thereof, but it is to be understood that these are not intended to be exhaustive nor limiting of the invention, but on the contrary are given for purposes of illustration in order that others skilled in the art may fully understand the invention and the man nor of applying it in practical use so that they may modify and adapt it in various forms, each as may be best suited to the conditions of a particular use.

The various objects, aspects and advantages of the present invention will [be more fully understood from a consideration of the following specification in conjunction with the accompanying drawings, wherein corresponding reference numerals, with appropriate suffixes are used in the various figures to indicate parts and elements performing corresponding functions, and in which:

FIGURE 1 is a perspective view of a pair of die members embodying the present invention;

FIGURE 2 is an enlarged elevational view looking along the axis of the opening defined by the die faces of the die members of FIGURE 1 in closed position;

FIGURE 3 is a similar elevational view of another pair of die members embodying the present invention in modified form shown in closed position; and

FIGURES 4 and 5 are elevational views of the die members of FIGURES 1 and 2, showing, in section, a connector ferrule and an electrically conductive core positioned between the die faces, with the die members positioned at the beginning and at an intermediate stage, respectively, of the crimping operation.

As shown in FIGURES 1 and 2, the first die member, generally indicated at 10, has a die face, generally indicated at 12, including an indented working port-ion formed by a nest portion 114 with a pair of sides 15 and 16 forming a dihedral angle. The die face 12 also includes a pair of extension surfaces 17 and 18 contiguous with the nest 14 and extending tangentially from the opposite sides 15 and 16, respectively, of the nest portion. As seen in outline in FIGURE 2, the die [face extension surfaces 17 and 18 are substantially straight and diverge at an angle lying in the range from about 60 to about The nest 14 is shown in FIGURE 2 as being generally V- shaped with a rounded vertex 20 between its two sides 15 and 16.

It is usually desirable to have the sides 15 and 16 planar, with the extension surfaces 17 and 18 also being planar and extending tangential-1y out from the sides.

3 The vertex 20 is curvilinear and tangent to the two sides 15 and 16. In this illustrative embodiment, the sides 15 and 16 are approximately perpendicular to each other.

In operation, the work material, shown illustratively in FIGURES 4 and 5 as including a connector ferrule 22 with an electrical conductor core 24 therein, is rested in the nest 14 with the axis of the ferrule and conductor parallel with the longitudinal axis of the die face 12. And a second die member, generally indicated at 30, with the die face 32 opposite the die face 12 is closed toward the die member in a direction 33, generally transversely to the longitudinal axis of the die faces 12 and 32.

This die face 32 includes a nest portion 34, as shown in FIGURE 2., being generally V-shaped and having substantially straight sides 35 and 36 also forming a dihedra-l angle a rounded vertex 40 therebetween.

It is usually desirable to have the sides 35 and 36 planar, with the rounded vertex 40 being curvilinear and tangent to them. In this illustrative embodiment, the sides 35 and 36 are also perpendicular to each other and are equal to the effective size of the sides 15 and 16 of the nest 14, as explained hereinafter.

Adjoining either side of the nest 34 are a pair of shoulders with surfaces 42 and 44, respectively, sloping back at an angle equal to the angle between the extension surf-aces 17 and 18 of the other die face so as to fit flushly thereagainst.

As the die members 10 and 30 move toward each other, the ferrule 22 and core 24 are deformed into a rhombic form, as illustrated in FIGURES 4 and 5. During closure of the dies, the work material extrudes radially outwardly to fi-ll the rounded vertice and 40.

Also, the work material tends to extrude radially out into the parting space between the die face extension 17 and the shoulder surface 42, and into the parting space between the die face extension 18 and the shoulder surface 44. These parting spaces are of equal width. The initial width at the beginning of the crimping action of one of these parting spaces is indicated as S in FIG- URE 4.

Advantageously, an effective confining action-is obtained preventing the work material from extruding out into these parting spaces and avoiding the formation of any flash portions on the connection. As the ferrule 22 tends to be extruded radially further and further out along the sides 15 and 16, it continually encounters resistance because it is in continued contact with these sides and with their tangential extensions 17 and 18, which are acting to wedge the material of the ferrule back into the desired region.

Moreover, the inclination of these surfaces 1 and 18 and the complementary shape of the shoulder surfaces 42 and 44 produces a geometrical advantage with respect to the ratio between the width of the parting space, i.e., S and the die travel distance D remaining before the dies reach their fully closed position. This parting space S i consider-ably smaller than the die travel D and advantageously continues to be smaller. This geometrical advantage becomes more and more important as the die members approach closely to their fully closed position. As shown in FIGURE 5 with the die members nearly closed, the width of the parting space S is considerably smaller than the remaining die travel distance D Where the die face extensions 17 and 18 are symmetrically positioned with respect to the direction 33 of die closure, then the ratio between the width of the parting space and the remaining die travel distance is expressed -as follows:

4 about 60 to about this ratio has a value in the range from about .5 to about .866.

Thus, the material of the ferrule and conductor is effectively confined within the two nests 14 and 34 and is crimped into a rhombic-shaped connection, with the extruded material flowing axially of the connection.

In result, the material of the ferrule is laterally confined by two effects, the wedging action of the sides 15 and 16, in combination with their tangential extensions 17 and 18, and the action of the inclined parting spaces producing an effectively more rapid closure of the parting space than the remaining die travel distance. When the dies are fully closed, these shoulder surfaces 42 and 44 bear ilushly against the extension surfaces 17 and 18.

The phantom dotted lines in FIGURE 2 illustrate the way in which the die member 10 is used as a universal die to crimp an extremely Wide range of sizes of connections. In order to crimp larger or smaller connections, the upper die 30 is replaced by any one of a set of generally similar dies. These all have V-shaped nests with a pair of straight converging sides 35' and 36' of graduated lengths in the different size die faces and with a rounded vertex 40' of the same size in all of these dies and equal to the vertex 20.

The relative extent of the nest sides 15 and 16 and the die face extensions 17 and 18 in each case is determined by the size of the die face 32 of the die member 30. But in each case the sides 15 and 16 are effectively equal to the side 35 and 36 to form a rugged, durable, rhombic-shaped connection.

As used herein, rhombic or similar expression is intended to include any parallelogram form having approximately equal sides and expressly includes a square.

The die members 1011 and 30a in FIGURE 3 form a regular equilateral pentagonal crimp. The die face of the die member 10 includes a V-shaped nest portion 14a with .a pair of substantially straight sides 15a and 16a, and has a pair of extension surfaces 171: and 18a adjoining the nest 14a and extending tangentially from its opposite sides. These extension surfaces are shown diverging at an angle of about 108i. It is usually desirable to have these side planar, with the rounded vertex 20a being a curvilinear cavity tangent thereto.

The die number 30a has a die face including a general U-shaped nest portion 34a. The sides 35a and 36a of the nest cavity are substantially straight, as seen in outline, and diverge at an angle of about 36". The bottom 46 is flat and perpendicular to the direction of die closure 33a and is joined to the sides 35a and 36a by rounded corners 47 and 4%. The included angles between each of these sides and the bottom is about 108 and desirably these sides and the bottom are planar, with the corners 4-7 and 48 being curvilinear and tangential thereto.

For crimping a wide range of sizes of connections, the die member 30a is replaced by any one of a set of dies having nests 34a of graduated size, as indicated by the dotted outlines of their die faces. An effective confined crimping action is advantageously obtained similar to that described above, as will be understood from the foregoing description.

From the foregoing, it will be understood that the embodiments of the present invention described above are well suited to provide the advantages set forth, and since many possible embodiments may be made of the various features of this invention, and as the apparatus herein described may be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limting sense, and that in certain instances some of the features of the invention may be used without a corresponding use of other features, or without departing from the scope of the invention.

I claim:

r1. A series of dies of different sizes, each die of said series adapted to cooperate with a larger die to form a dieset to make a crimped connection between a metal ferrule and a conductor, wherein the ferrule is entirely supported by the dieset after completion of the crimping operation, each of said dies having crimping faces terminating in a vertex to form a first angle, said crimping faces forming a V in cross section, each die of said series having identical angles, but successively shorter crimping faces forming the sides of the angle, each of said dies of the series adapted to nest within said larger die constituted by a longer crimping face.

2. A series of dies of different sizes, each die of said series adapted to cooperate with a larger die to form a dieset to make a crimped connection between a metal ferrule and a connector, wherein the ferrule is entirely supported by the dieset after completion of the crimping operation, each of said dies having crimping faces formed by dihedral angles terminating in a vertex to form a first angle, said crimping faces forming a V in cross section, each die of said series having identical angles, but successively shorter crimping faces forming the sides of the angle, each of said dies of the series adapted to nest within said larger die constituted by a longer crimping face, a pair of shoulders in each of said dies in the series, said shoulders comprising rectangular faces, each forming a dihedral angle with one of said working faces, and all of said dihedral angles being equal.

References Cited in the file of this patent UNITED STATES PATENTS 1,?A-1,377 Hebert Sept. 25, 1917 1,677,968 Hughes July 24, 1928 2,427,518 Bergan Sept. 16, 1947 2,534,867 Hennessey Dec. 19, '1950 

1. A SERIES OF DIES OF DIFFERENT SIZES, EACH DIE OF SAID SERIES ADAPTED TO COOPERATE WILT A LARGE DIE TO FORM A DIESET TO MAKE A CRIMPED CONNECTION BETWEEN A METAL FERRULE AND A CONDUCTOR, WHEREIN THE FERRULE IS ENTIRELY SUPPORTED BY THE DIESET AFTER COMPLETION OF THE CRIMPING OPERATION, EACH OF SAID DIES HAVING CRIMPING FACES TERMINATING IN A VERTEX TO FORM A FIRST ANGLE, SAID CRIMPING 